Editing Triassic–Jurassic extinction event (section)

===Terrestrial plants===
The extinction event marks a floral turnover as well, with estimates of the percentage of Rhaetian pre-extinction plants being lost ranging from 17% to 73%.<ref>{{cite journal |last1=Lindström |first1=Sofie |date=1 September 2015 |title=Palynofloral patterns of terrestrial ecosystem change during the end-Triassic event – a review |url=https://pubs.geoscienceworld.org/geolmag/article-abstract/153/2/223/251206/Palynofloral-patterns-of-terrestrial-ecosystem?redirectedFrom=fulltext |journal=[[Geological Magazine]] |volume=153 |issue=2 |pages=223–251 |doi=10.1017/S0016756815000552 |s2cid=131410887 |access-date=28 May 2023}}</ref> Though spore turnovers are observed across the Triassic-Jurassic boundary, the abruptness of this transition and the relative abundances of given spore types both before and after the boundary are highly variable from one region to another, pointing to a global ecological restructuring rather than a mass extinction of plants.<ref name="BarbackaEtAlPPP2">{{cite journal |last1=Barbacka |first1=Maria |last2=Pacyna |first2=Grzegorz |last3=Kocsis |first3=Ádam T. |last4=Jarzynka |first4=Agata |last5=Ziaja |first5=Jadwiga |last6=Bodor |first6=Emese |date=15 August 2017 |title=Changes in terrestrial floras at the Triassic-Jurassic Boundary in Europe |url=https://www.sciencedirect.com/science/article/abs/pii/S0031018216304977 |journal=[[Palaeogeography, Palaeoclimatology, Palaeoecology]] |volume=480 |pages=80–93 |bibcode=2017PPP...480...80B |doi=10.1016/j.palaeo.2017.05.024 |access-date=12 December 2022}}</ref> Overall, plants suffered minor diversity losses on a global scale as a result of the extinction, but species turnover rates were high and substantial changes occurred in terms of relative abundance and growth distribution among taxa.<ref>{{Cite journal |last1=McElwain |first1=Jennifer C. |last2=Popa |first2=Mihai E. |last3=Hesselbo |first3=Stephen P. |last4=Haworth |first4=Matthew |last5=Surlyk |first5=Finn |date=December 2007 |title=Macroecological responses of terrestrial vegetation to climatic and atmospheric change across the Triassic/Jurassic boundary in East Greenland |url=http://dx.doi.org/10.1666/06026.1 |journal=Paleobiology |volume=33 |issue=4 |pages=547–573 |doi=10.1666/06026.1 |bibcode=2007Pbio...33..547M |s2cid=129330139 |issn=0094-8373}}</ref> Evidence from Central Europe suggests that rather than a sharp, very rapid decline followed by an adaptive radiation, a more gradual turnover in both fossil plants and spores with several intermediate stages is observed over the course of the extinction event.<ref>{{cite journal |last1=Gravendyck |first1=Julia |last2=Schobben |first2=Martin |last3=Bachelier |first3=Julien B. |last4=Kürschner |first4=Wolfram Michael |date=November 2020 |title=Macroecological patterns of the terrestrial vegetation history during the end-Triassic biotic crisis in the central European Basin: A palynological study of the Bonenburg section (NW-Germany) and its supra-regional implications |url=https://www.sciencedirect.com/science/article/abs/pii/S0921818120301776 |journal=[[Global and Planetary Change]] |volume=194 |page=103286 |bibcode=2020GPC...19403286G |doi=10.1016/j.gloplacha.2020.103286 |hdl=1874/409017 |s2cid=225521004 |access-date=12 December 2022|hdl-access=free }}</ref> Extinction of plant species can in part be explained by the suspected increased carbon dioxide in the atmosphere as a result of CAMP volcanic activity, which would have created [[photoinhibition]] and decreased transpiration levels among species with low photosynthetic plasticity, such as the broad leaved [[Ginkgoales]] which declined to near extinction across the Tr–J boundary.<ref name=":02">{{Cite journal |last1=Yiotis |first1=C. |last2=Evans-Fitz.Gerald |first2=C. |last3=McElwain |first3=J. C. |date=2017-03-11 |title=Differences in the photosynthetic plasticity of ferns and Ginkgo grown in experimentally controlled low [O2]:[CO2] atmospheres may explain their contrasting ecological fate across the Triassic–Jurassic mass extinction boundary |url=http://dx.doi.org/10.1093/aob/mcx018 |journal=Annals of Botany |volume=119 |issue=8 |pages=1385–1395 |doi=10.1093/aob/mcx018 |pmid=28334286 |pmc=5604595 |issn=0305-7364}}</ref>

Ferns and other species with dissected leaves displayed greater adaptability to atmosphere conditions of the extinction event,<ref>{{Cite journal |last1=Bos |first1=Remco |last2=Lindström |first2=Sofie |last3=van Konijnenburg-van Cittert |first3=Han |last4=Hilgen |first4=Frederik |last5=Hollaar |first5=Teuntje P. |last6=Aalpoel |first6=Hendrik |last7=van der Weijst |first7=Carolien |last8=Sanei |first8=Hamed |last9=Rudra |first9=Arka |last10=Sluijs |first10=Appy |last11=van de Schootbrugge |first11=Bas |date=1 September 2023 |title=Triassic-Jurassic vegetation response to carbon cycle perturbations and climate change |journal=[[Global and Planetary Change]] |volume=228 |pages=104211 |doi=10.1016/j.gloplacha.2023.104211 |bibcode=2023GPC...22804211B |issn=0921-8181 |doi-access=free }}</ref> and in some instances were able to proliferate across the boundary and into the Jurassic.<ref name=":02" /> The species ''[[Lepidopteris|Lepidopteris ottonis]]'' evolved a reliance on asexual reproduction amidst the environmental chaos of the TJME.<ref>{{Cite journal |last=Vajda |first=Vivi |last2=McLoughlin |first2=Stephen |last3=Slater |first3=Sam M. |last4=Gustafsson |first4=Ola |last5=Rasmusson |first5=Allan G. |date=1 October 2023 |title=The ‘seed-fern’ Lepidopteris mass-produced the abnormal pollen Ricciisporites during the end-Triassic biotic crisis |url=https://www.sciencedirect.com/science/article/pii/S0031018223003413 |journal=[[Palaeogeography, Palaeoclimatology, Palaeoecology]] |language=en |volume=627 |pages=111723 |doi=10.1016/j.palaeo.2023.111723 |access-date=18 February 2025 |via=Elsevier Science Direct}}</ref> In the Jiyuan Basin of North China, ''Classopolis'' content increased drastically in concordance with warming, drying, wildfire activity, enrichments in isotopically light carbon, and an overall reduction in floral diversity.<ref>{{Cite journal |last1=Zhang |first1=Peixin |last2=Lu |first2=Jing |last3=Yang |first3=Minfang |last4=Bond |first4=David P. G. |last5=Greene |first5=Sarah E. |last6=Liu |first6=Le |last7=Zhang |first7=Yuanfu |last8=Wang |first8=Ye |last9=Wang |first9=Ziwei |last10=Li |first10=Shan |last11=Shao |first11=Longyi |last12=Hilton |first12=Jason |date=28 March 2022 |title=Volcanically-Induced Environmental and Floral Changes Across the Triassic-Jurassic (T-J) Transition |journal=[[Frontiers in Ecology and Evolution]] |volume=10 |pages=1–17 |doi=10.3389/fevo.2022.853404 |issn=2296-701X |doi-access=free }}</ref> In the [[Sichuan Basin]], relatively cool mixed forests in the late Rhaetian were replaced by hot, arid fernlands during the Triassic–Jurassic transition, which in turn later gave way to a cheirolepid-dominated flora in the Hettangian and Sinemurian.<ref>{{cite journal |last1=Li |first1=Liqin |last2=Wang |first2=Yongdong |last3=Kürschner |first3=Wolfram M. |last4=Ruhl |first4=Micha |last5=Vajda |first5=Vivi |date=15 October 2020 |title=Palaeovegetation and palaeoclimate changes across the Triassic–Jurassic transition in the Sichuan Basin, China |url=https://www.sciencedirect.com/science/article/abs/pii/S0031018220303369 |journal=[[Palaeogeography, Palaeoclimatology, Palaeoecology]] |volume=556 |page=109891 |bibcode=2020PPP...55609891L |doi=10.1016/j.palaeo.2020.109891 |s2cid=225600810 |access-date=22 May 2023}}</ref> The abundance of ferns in China that were resistant to high levels of aridity increased significantly across the Triassic–Jurassic boundary, though ferns better adapted for moist, humid environments declined, indicating that plants experienced major environmental stress, albeit not an outright mass extinction.<ref>{{cite journal |last1=Zhou |first1=Ning |last2=Xu |first2=Yuanyuan |last3=Li |first3=Liqin |last4=Lu |first4=Ning |last5=An |first5=Pengcheng |last6=Popa |first6=Mihai Emilian |last7=Kürschner |first7=Wolfram Michael |last8=Zhang |first8=Xingliang |last9=Wang |first9=Yongdong |date=October 2021 |title=Pattern of vegetation turnover during the end-Triassic mass extinction: Trends of fern communities from South China with global context |journal=[[Global and Planetary Change]] |volume=205 |page=103585 |bibcode=2021GPC...20503585Z |doi=10.1016/j.gloplacha.2021.103585 |doi-access=free}}</ref> In some regions, however, major floral extinctions did occur, with some researchers challenging the hypothesis of there being no significant floral mass extinction on this basis. In the [[Newark Supergroup]] of the [[East Coast of the United States|United States East Coast]], about 60% of the diverse monosaccate and bisaccate pollen assemblages disappear at the Tr–J boundary, indicating a major extinction of plant genera. [[Early Jurassic]] [[pollen]] assemblages are dominated by ''Corollina'', a new genus that took advantage of the empty [[Niche segregation|niches]] left by the extinction.<ref name="Fowell19942">{{Citation |last1=Fowell |first1=S. J. |title=Geologically rapid Late Triassic extinctions: Palynological evidence from the Newark Supergroup |date=1994 |work=Geological Society of America Special Papers |pages=197–206 |publisher=Geological Society of America |doi=10.1130/spe288-p197 |isbn=978-0813722887 |last2=Cornet |first2=B. |last3=Olsen |first3=P. E.}}</ref> The site of St. Audrie's Bay displays a shift from diverse gymnosperm-dominated forests to Cheirolepidiaceae-dominated monocultures.<ref name="BonisAndKurschner2012" /> The Danish Basin saw 34% of its Rhaetian spore-pollen assemblage, including ''Cingulizonates rhaeticus'', ''Limbosporites lundbladiae'', ''Polypodiisporites polymicroforatus'', and ''Ricciisporites tuberculatus'', disappear, with the post-extinction plant community being dominated by pinacean conifers such as ''Pinuspollenites minimus'' and tree ferns such as ''Deltoidospora'', with ginkgos, cycads, cypresses, and corystospermous seed ferns also represented.<ref>{{Cite journal |last1=Lindström |first1=Sofie |last2=Erlström |first2=Mikael |last3=Piasecki |first3=Stefan |last4=Nielsen |first4=Lars Henrik |last5=Mathiesen |first5=Anders |date=September 2017 |title=Palynology and terrestrial ecosystem change of the Middle Triassic to lowermost Jurassic succession of the eastern Danish Basin |url=https://linkinghub.elsevier.com/retrieve/pii/S0034666716300318 |journal=[[Review of Palaeobotany and Palynology]] |language=en |volume=244 |pages=65–95 |doi=10.1016/j.revpalbo.2017.04.007 |access-date=28 March 2024 |via=Elsevier Science Direct}}</ref> Along the margins of the European Epicontinental Sea and the European shores of the Tethys, coastal and near-coastal mires fell victim to an abrupt sea level rise. These mires were replaced by a pioneering opportunistic flora after an abrupt sea level fall, although its heyday was short lived and it died out shortly after its rise.<ref>{{cite journal |last1=Lindström |first1=Sofie |date=17 September 2021 |title=Two-phased Mass Rarity and Extinction in Land Plants During the End-Triassic Climate Crisis |journal=[[Frontiers in Earth Science]] |volume=9 |page=1079 |bibcode=2021FrEaS...9.1079L |doi=10.3389/feart.2021.780343 |doi-access=free}}</ref> The opportunists that established themselves along the Tethyan coastline were primarily spore-producers.<ref name="BonisAndKurschner2012">{{Cite journal |last1=Bonis |first1=Nina R. |last2=Kürschner |first2=Wolfram M. |date=2012 |title=Vegetation history, diversity patterns, and climate change across the Triassic/Jurassic boundary |url=https://www.cambridge.org/core/product/identifier/S0094837300000567/type/journal_article |journal=[[Paleobiology (journal)|Paleobiology]] |language=en |volume=38 |issue=2 |pages=240–264 |doi=10.1666/09071.1 |issn=0094-8373 |access-date=28 March 2024 |via=Cambridge Core}}</ref> In the Eiberg Basin of the [[Northern Calcareous Alps]], there was a very rapid palynomorph turnover.<ref>{{cite journal |last1=Bonis |first1=N. R. |last2=Kürschner |first2=W. M. |last3=Krystyn |first3=L. |date=September 2009 |title=A detailed palynological study of the Triassic–Jurassic transition in key sections of the Eiberg Basin (Northern Calcareous Alps, Austria) |url=https://www.sciencedirect.com/science/article/abs/pii/S0034666709000633 |journal=[[Review of Palaeobotany and Palynology]] |volume=156 |issue=3–4 |pages=376–400 |bibcode=2009RPaPa.156..376B |doi=10.1016/j.revpalbo.2009.04.003 |access-date=28 May 2023}}</ref> The palynological and palaeobotanical succession in Queensland shows a ''Classopolis'' bloom after the TJME.<ref>{{Cite journal |last1=de Jersey |first1=Noel J. |last2=McKellar |first2=John L. |date=15 January 2013 |title=The palynology of the Triassic–Jurassic transition in southeastern Queensland, Australia, and correlation with New Zealand |url=http://www.tandfonline.com/doi/abs/10.1080/01916122.2012.718609 |journal=Palynology |language=en |volume=37 |issue=1 |pages=77–114 |doi=10.1080/01916122.2012.718609 |issn=0191-6122 |access-date=19 June 2024 |via=Taylor and Francis Online}}</ref> [[Polyploidy]] may have been an important factor that mitigated a conifer species' risk of going extinct.<ref>{{cite journal |last1=Kürschner |first1=Wolfram M. |last2=Batenburg |first2=Sietske J. |last3=Mander |first3=Luke |date=7 October 2013 |title=Aberrant Classopollis pollen reveals evidence for unreduced (2n) pollen in the conifer family Cheirolepidiaceae during the Triassic–Jurassic transition |journal=[[Proceedings of the Royal Society B: Biological Sciences]] |volume=280 |issue=1768 |pages=1–8 |doi=10.1098/rspb.2013.1708 |pmc=3757988 |pmid=23926159}}</ref>